I was in the Johto safari zone, and I threw mud at a ditto. Instead of simply saying that the ditto was angry, it said that "it lost its head in anger!" or something. Is it any different from just it being angry? (I only threw mud at it once)
I'm fairly sure that indicates it's severely close to fleeing. Whenever it happens, either throw bait or throw a Poke Ball and hope you catch it. Throwing mud will only end up making it run away.